472 MICROSCOPICAL OBSERVATIONS 



Rocks of all ages, including those in which organic 

 remains have never been found, yielded the molecules in 

 abundance. Their existence was ascertained in each of the 

 constituent minerals of granite, a fragment of the Sphinx 

 being one of the specimens examined. 



To mention all the mineral substances in which I have 

 found these molecules, would be tedious ; and I shall con- 

 fine myself in this summary to an enumeration of a few of 

 the most remarkable. These were both of aqueous and 

 igneous origin, as travertine, stalactites, lava, obsidian, 

 10] pumice, volcanic ashes, and meteorites from various locali- 

 ties.^ Of metals I may mention manganese, nickel, plum- 

 bago, bismuth, antimony, and arsenic. In a word, in every 

 mineral which I could reduce to a powder, sufficiently fine 

 to be temporarily suspended in water, I found these mole- 

 cules more or less copiously ; and in some cases, more par- 

 ticularly in siliceous crystals, the whole body submitted to 

 examination appeared to be composed of them. 



In many of the substances examined, especially those of 

 a fibrous structure, as asbestus, actinolite, tremolite, zeolite, 

 and even steatite, along with the spherical molecules, other 

 corpuscles were found, like short fibres somewhat monili- 

 form, whose transverse diameter appeared not to exceed that 

 of the molecule, of which they seemed to be primary com- 

 binations. These fibrils, when of such length as to be 

 probably composed of not more than four or five molecules, 

 and still more evidently when formed of two or three only, 

 were generally in motion, as least as vivid as that of the 

 simple molecule itself; and which from the fibril often 

 changing its position in the fluid, and from its occasional 

 bending, might be said to be somewhat vermicular. 



In other bodies which did not exhibit these fibrils, oval 

 particles of a size about equal to two molecules, and which 

 were also conjectured to be primary combinations of these, 

 were not unfrequently met with, and in motion generally 

 more vivid than that of the simple molecule ; their motion 

 consisting in turning usually on their longer axis, and then 



' I have since found the molecules in the sand-tubes, formed bj lightning, 

 from Drig in Cumberland. 



